Wondering about software to treat the Double-Digest Problem

Greetings! Can somebody out there in Bionetland tell me if publicly
accessible software exists for handling Double- or Multiple-Digest
Problems?
I am aware that these are difficult computational problems, pretty
much intractable, for a number of reasons. However, I have a user
facing fairly "small" instances of DDP/MDP, and he could be aided by
some automated form of attack, accepting that suggested solutions
might come with no guarantee of correctness or optimality.
We would also be interested in hearing about public-domain software
which could assist the planning of successive digests for purposes
of restriction mapping, that is, a tool which could compute and
somehow highlight remaining ambiguities in restriction site order.
Note: I am not a subscriber to this group so please reply to me
directly. Thanks in advance for any help!
Mark Reboul
Columbia University Cancer Center Computing Facility
mark at cuccfa.ccc.columbia.edu